Might there once have been life on Mars? Might there still be?
The surface of Mars is now a frigid desert, but it was not always so. Three to four billion years ago, soon after our Solar System formed, the climates of Earth and Mars were similar. At that time there certainly was life on Earth. If it was here, why not on Mars too?

Now the greatest exploration program in history is under way: the search for the origin of life on Earth, and for life beyond Earth. A veritable armada of spacecraft is unlocking the secrets of the Red Planet and more missions are planned.

Malcolm Walter has worked with NASA scientists for more than a decade helping to determine where to look for fossil life on Mars. In this book he provides an insight into the exhilarating, frustrating and occasionally acrimonious world of palaeobiology as he tells the story of humankind's search for life on Mars.

Walter skilfully conveys the enormous difficulty of searching for and identifying life on another world. This is a truly inspirational account of the greatest adventure in history told by one of its most influential players.